Sectional gears



H. Y. LEE

SECTIONAL GEARS June 5, 1956 2 Sheets-Sheet 1 Filed April 9, 1953 INVENTOR ATTORNEY H. Y. LEE

SECTIONAI.. GEARS June 5, 1956 Filed April 9, 1953 2 Sheets-Sheet 2 T'll HENRY Y LEE ATTORNEY INV ENTOR United States Patent C) v This invention relates to sectional gears, and more particularly to sectional gears which are divided transversely of their axes of rotation and comprising a pair of aligned and peripherally toothed elements.

It is well-known that the subjection of gears of all types to repeated forces of bending, pressure and friction results in gradual wear on the gear teeth and fatigue of the metal of which they are composed, thereby requiring frequent repair or replacement. This is particularly true of peripherally toothed gears.

In the case of herringbone gears, both their production and repair are considerably more diicult and require a more specialized type of skill and equipment than for such gears as spur, bevel, spiral, etc.

It is among the objects of the present invention to substantially reduce the disadvantages set forth hereinabove by providing a sectional gear structure which is comparatively inexpensive and easy to manufacture, and yet eflicient and durable in service.

Another object is the attainment of the foregoing objectives with a sectional gear which may be easily and speedily repaired or replaced.

Still another object is to provide a peripherally toothed gear of the herringbone type which is possessed of the foregoing characteristics.

A further object is to provide an improved gear of the type referred to which is characterized by improved distribution of the load from the fastening instrumentalities.

A still further object is the provision in a gear of the class described of means enabling certain of the component parts to be made from stocks of standard shape and of different metals as determined by the use for which they are intended.

The invention, then, comprises the features fully described, and as particularly pointed out in the claims, the following description and annexed drawings setting forth in detail illustrative embodiments of the invention, these being indicative of but several of a number of ways in which the principles of the invention may be employed.

In said drawings:

Figure l is a perspective illustrating two herringbone gears, both of which have been constructed in accordance with the teachings of the present invention, the bottom and larger herringbone gear of this pair being provided with a hub and web assembly, while the upper and smaller herringbone gear is of a webless type;

Figure 2 is an enlarged fragmentary elevational view of the upper and smaller herringbone gear of Figure 1;

Figure 3 is a sectional view on the line 3-3 of Figure 2;

Figure 4 is an enlarged fragmentary elevational View of the lower and larger gear of Figure 1 (the same comprising a hub and web assembly);

Figure 5 is a sectional view on the line 5-5 of Figure 4;

Figure 6 is a view similar to the showing of Figure 1, but illustrating a pair of upper and lower gears of the pug-nose herringbone type;

Figure 7 is an enlarged perspective, partly in section, of the smaller and upper gear of the showing of Figure 6;

Figure 8 is an end elevation of the gear of Figure 7;

Figure 9 is a sectional view on the line 9 9 of Figure 8;

Figure l0 is an enlarged elevational View of the lower and larger pug-nose herringbone gear of Figure 6; and

Figure 1l is a sectional view on the line 11--11 of Figure 10.

Referring more particularly to the drawings, the upper and smaller of the two herringbone gears of Figure 1 comprises a left-hand gear section 10 and a right-hand section 11, the said sections' being divided or split transversely of their axes of rotation and adapted for closely abutting relationship. The peripheries of these gear sections 10 and 11 are provided with oblique or helical teeth 12 of identical shape and size; whereby the said sections may be so assembled as to form the composite V- shaped teeth which characterize a herringbone gear. The peripherally toothed gear sections 10 and 11 are centrally bored, as at 13, to receive a gear shaft; and, after proper alignment, the sections are bonded together by countersunk cap screws 14 which extend from the body portion of one section and engage aligned screw-threaded recesses 15 in the body portion of the opposite section.

Preferably, the cap screws 14 and recesses 15 therefor are at evenly spaced points, as shown in Figure 2.

The shaft on which the sectional gear is to be mounted carries a shaft collar 16 and opposed shaft nut 17, these instrumentalities being adapted to occupy correspondingly shaped recesses 18 on the outside cheeks of the gear sections (see Figure 3), such construction providing additional bondage.

The lower and larger herringbone gear of Figure 1 comprises a conventional hub with a web 19 having a machine-iinished circumferential rim 20 (see Figure 5) which occupies correspondingly shaped opposed recesses 21 in left-hand and right-hand gear bands 22 and 23, respectively. As shown, the peripheries of the left-hand and right-hand gear bands are provided with oblique or helical teeth 12 in the manner of the previously described webless gear sections 10 and 11.

Referring still to Figure 5, each of the opposed recesses 21 (in the left-hand and right-hand gear bands 22 and 23, respectively) is of a depth suiicient to accommodate one-half of the thickness of the machinefinished circumferential rim 20, whereby the latter is fully encased. Each of the left-hand and right-hand gear bands (i. e., 22 and 23) is provided with a flange 24 which extends inwardly of, and perpendicularly with respect to, the inner surfaces of toothed periphery of each gear band, the said flanges forming extensions of the inner faces of the aforementioned opposed recesses 21. According to such construction, the gear bands 22 and 23 may be bonded together, and to the machinefinished circumferential rim 20 of the web 19, by means of bolts 25 and locked-nuts 26, the said bolts extending through anchor holes 27 in the aforementioned flanges 24 and anchor holes 28 in said rim 20.

In the case of either the webless gear comprising the gear sections 10 and 11 or the web-type gear comprising the gear bands 22 and 23, alignment, setting or identification of the gear teeth may be made on the exterior cheeks of the toothed elements by means of punched markings 29 (see Figures 2 and 4).

In View of the fact that the maximum force exerted on the teeth of herringbone gears is at the junction of the helical teeth, it is at such points that repair is most frequently required; and one of the most important objectives of the present invention is to provide a sectional gear which is analogous to the gears of Figures 1 through Patented June 5, 1956' 5, but which is characterized by increased strength at the mid-section of the toothed peripheries of the gear components. Such increased strength accrues from the pug-nose herringbone gear shown in Figures 6 through 11.

The upper and smaller gear of Figure 6 is,.like the corresponding gear of Figure l, of the webless type. The mid-section of this webless pugnose herringbone gear is indicated by the reference numeral 30, the same having peripheral teeth 31 in the manner of a conventional spur gear. This mid-sectional element 3i) is sandwiched between, and bonded to,.a left-hand helical gear section 32 on the one side, and a right-hand helical gear section 33 on the other side, the said helical gear sections 32 and 33 having like diameters with the midsectional element 30, and the adjoining ends of the helical gear teeth 34 (of both the left and right-hand helical gear sections) being alignedL with the aforementioned teeth 31.

The gear sections 30, 32 and 33 are bonded together in laminar relationship to form a complete gear by means of machine screws 35 which are received in aligned screwthreaded anchor holes 36 in the respective sections. The shaft on which the small pug-nose herringbone gear is mounted is indicated at` 37; and it is provided with a shaft collar 38 and opposed shaft nut 39, these elements being adapted to occupy correspondingly shaped recesses 40 on the outside faces of the gear sections 30 and 32.

As will be readily understood by those skilled inthe art, the screw threads 43'for the shaft nut 39 may be formed on a radially enlarged portion of the shaft 37, as shown in Figure 7; or the threads (for the shaft nut 39) may be cut directly into the appropriate portion of the shaft 37 with an adjacent portion of the latter reduced (as shown at 42 in Figure 9) to permit'the passage thereover of the shaft-nut.

The lower and larger pug-nose herringbone gear of Figure 6 comprises a web 44 carried by a hub 45, the periphery of the web being provided'with teeth 46 ofthe spur gear type. The numerals 47 and 48, respectively, designate the left-hand and right-hand gear bands, the peripheries of which are provided with oblique or helical gear teeth 49. The outside diameter, pitch diameter and number of teeth 49 on the gear bands 47 and 48 are the same as those of the spur teeth 46 of the web 44; and the respective teeth are, of course, aligned to form a pug-nose herringbone.

As shown most clearly in Figure l1, each of the lefthand and right-hand gear bandsr47 and 48 is provided with a ange 50 which extendsinwardly of, Aand atrrightangles to, the toothed peripheries of said gear bands. These flanges 50 form extensions of the inner. faces of the gear bands and permit allithree of the toothed gear elements or sections to be secured or bonded'together by bolts 51 and locked-nuts-SZ, the bolts 51 extending4 through aligned anchor holes 53 in the web I44 and the flanges 50 on either side thereof.

As in the case of the embodiments described earlier herein, punch markings 54 onthe exposed surfaces of the gear bands 47 and 48 andthe intermediate web 44 may be used to identify, match or time the various elements.

While I have shown and described certain specic embodiments of the present invention, it will be readily understoodby those skilled in the art that I do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of the invention as defined in the appended claims.

l claim:

1. A sectional gear comprising a pair of similar and cooperative centrally apertured gear elements assembled about a rotatable shaft with the adjacent ends of their respective teeth aligned and'in'close contact with each other; the outer faces of` said gear elements having centrally disposed recesses; and means seating in said recesses for clamping said gear elements to each other and to said shaft, each of said gear elements being peripherally undivided.

2. A sectional gear comprising a pair of similar and cooperative centrally apertured gear elements assembled about a rotatable shaft with the adjacent ends of their respective teeth aligned and in close contact with each other; the outer faces of said gear elements-having centrally disposed recesses; means seating in said recesses for clamping said gear elements to each other and to said'shaft; and screw-threaded means spaced radially of said last-named means for additionally holding said gear elements in assembled relationship, each of said gear elements being peripherally undivided.

3. A sectional gear comprising a pair of similar and cooperative centrally apertured gear elements; a cooperative intermediate centrally apertured gear element; all of saidgear elements being assembled about a rotatable shaft with the outer ends of the teeth of said intermediate gear element aligned and in close contact with each other with the inner end of the teeth of said pair of similar gear elements; the outer faces of said pair of similar gear elements having centrally disposed recesses; and means seating in said recesses for clamping all of said gear elements to each other and to said shaft, each of said'gear elements being peripherally undivided.

4. A sectional gear comprising a pair of similar and cooperative centrally apertured gear elements; a cooperative intermediate centrally apertured gear element; all of said gear elements being assembled about a rotatable shaft with the outer ends of the teeth of said intermediate geary element aligned and in close contact with each other with the inner end of the teeth of said pair of similar gear elements; the outer faces of said pair of'similar gear elements having centrally disposed recesses; means seating in said recesses for clamping all of said. gear elements to each other and to said shaft; andserew-threaded means spaced radially of said last named means for additionally holding said gear elements in assembled relationship, each of said gear elements being peripherally undivided.

ReferencesCited in the tile of this patent UNITED STATES PATENTS 218,994 McCoy Mar. 15, 1879 415,044 Joslin Nov. l2, 1889 470,952. Scholtield Mar. 15, 1892 1,165,830 Alquist Dec. 28, 1915 

